A wide variety of tube feeding devices have been introduced which grip and then feed stock into processing machinery for further manipulation of the stock. Such devices are preferred over manual insertion of stock for several reasons. First, when stock is to be fed into operating machinery, it is generally safer to feed the stock into the machine using a mechanical device, rather than feeding the stock into the machine by hand. An example of such a device is the apparatus described in U.S. Pat. No. 2,003,152, which discloses a stock feeder for gripping and then feeding the stock into a turret lathe. Second, it is easier to feed precise lengths of stock into processing machinery, if required, when a mechanical apparatus is used to feed the stock. An example of such a device is that disclosed in U.S. Pat. No. 2,035,354.
In addition to the industrial applications mentioned above, stock feeding devices are also used in certain modern surgical techniques, such as the now well-known angioplasty surgery. These techniques typically require the insertion of a significant length of stock, or tubing, into an artery of the patient. For example, U.S. Pat. No. 4,615,472 discloses a catheter placement device for inserting a catheter into an artery for subsequent removal of plaque from the artery using well-known angioplasty techniques.
In the applications described above, it is sometimes necessary that the stock be rotated as it is fed into the processing machine or artery. For example, in the case of atherectomy surgery applications, several well-known devices are used to mechanically cut away arterial plaque by means of a rotating cutter at the end of a tube which has been inserted into the artery. Thus, the stock feeding devices used in such applications must be capable of gripping a rotating length of stock and then advancing (or retracting) the stock as required.
Accordingly, it is an object of the present invention to provide a stock feeder device which is relatively light weight and easy to use. It is another object of the present invention to provide a stock feeder device which can insert relatively precise lengths of stock into a channel. Still another object of the present invention is to provide a stock feeding device which can incrementally advance a piece of stock while it is being rotated. Another object of the present invention is to provide a stock feeder device which can grip and advance stock which has a wide range of diameters. Yet another object of the present invention is to provide a stock feeder device which is cost-effective to manufacture and which is capable of withstanding appropriate sterilization procedures.